Device for rapid detection of infectious agents

ABSTRACT

A portable system for real time detection of the presence of an infectious agent in a biological sample employs a reagent which detects the presence of a specific infectious agent in the sample, and emits a detectable signal when the reagent reacts with the sample and detects the presence of the infectious agent. A test cartridge has a reaction chamber for receiving the sample and the reagent. The reaction chamber has a predetermined internal geometry and at least one inner surface. Introducing the sample and the reagent into the test cartridge mixes the sample and the reagent. A testing unit receives the test cartridge, and includes a sensor for detecting an emitted detectable signal. The detection of the emitted detectable signal is indicative of the presence of the infectious agent in the sample.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/570,016 filed on Dec. 13, 2011 and entitled“Portable Detection Device,” the disclosure of which is herebyincorporated by reference herein in its entirety and made part of thepresent U.S. utility patent application for all purposes.

BACKGROUND OF THE INVENTION

The described invention relates in general to a system for detectingcontaminants in biological samples. More specifically, the presentinvention relates to a system for detecting infectious agents orpathogens in food samples in real time using a reagent such as abiosensor.

Previously, testing of samples for infectious agents was a timeconsuming and expensive process that was largely divorced from themanufacturing process. In order to test for the presence of aninfectious agent, a sample was typically enriched or cultured. Thisprocess requires the presence of a lab, and typically, the involvementof scientists with expertise in performing the required test. Due to theneed for additional culturing or enriching time, and specialized toolsand skills, the testing could not easily be performed on-site during themanufacturing process. As a consequence, the manufacturing process wastypically divorced from the testing process, resulting in the need forcostly recalls when the testing process later found the presence ofinfectious agents, and the like. In other settings, such as hospitals,delays in receiving test for infectious agents can allow for the spreadof such infectious agents.

Several proposals have been made to improve the speed of testing forinfectious agents by using biosensors for detection. For example,application of the aequorin-Ca2+ indicator to detect E. colicontamination in food products was reported by Todd H. Rider et al., A BCell-Based Sensor for Rapid Identification of Pathogens, SCIENCE, 11Jul. 2003, pp. 213-215, the entire disclosure of which is incorporatedherein by reference. However, the Rider process suffered from severaldrawbacks, such as a low signal-to-noise ratio that resulted in theprocess being undependable for use in large scale testing.

In generic terms, a biosensor is a system or device for the detection ofan analyte that combines a sensitive biological component with aphysicochemical detector component. The components of a typicalbiosensor system include a biological element, a transducer or detectorelement, and associated electronics or signal processors that displaytest results in a meaningful and useful manner. The biological elementincludes biological material such as tissue, microorganisms, organelles,cell receptors, enzymes, antibodies, nucleic acids, and the like thatmay be created by known biological engineering processes. The transduceror detector element works in a physicochemical manner (e.g., optical,piezoelectric, and/or electrochemical) that transforms a signalresulting from the interaction of the analyte with the biologicalelement into another signal that can be more easily measured andquantified. Biosensors originated from the integration of molecularbiology and information technology (e.g., microcircuits, optical fibers,etc.) to qualify or quantify biomolecule-analyte interactions such asantibody-antigen interactions.

There is demand for rapid, sensitive, easy-to-handle, and cost-effectivedetection tools to detect infectious agents, pathogens or/and toxins infood (see, for example, Mead et al., Food Related Illness and Death inthe United States, Emerging Infectious Diseases; Vol. 5, No. 5,September-October 1999 (607-625), which is incorporated by referenceherein).

Accordingly, it is desirable to provide a portable, self-containedsystem capable of rapidly testing samples for infectious agents in realtime or near real time. It is further desirable to improve the techniqueof using biosensors for testing samples for infectious agents byimproving the signal-to-noise ratio. It is further desirable to providea testing device capable of being used by general staff for testingfoodstuffs while in the manufacturing process.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a system for rapidly detecting the presence of aninfectious agent in a biological sample is described. A first reagent isoperative to detect the presence of a specific infectious agent in asample to be tested, and to emit a detectable signal when the firstreagent reacts with the sample and detects the presence of the specificinfectious agent in the sample. A test cartridge has a reaction chamberfor receiving the sample and the first reagent. The reaction chamber hasa predetermined internal geometry and at least one inner surface.Introducing the sample and the first reagent into the test cartridgemixes the sample and the first reagent. A testing unit receives the testcartridge, and includes a sensor for detecting an emitted detectablesignal. The detection of the emitted detectable signal is indicative ofthe presence of the infectious agent in the sample. Detection of thespecific infectious agent in the sample occurs in real time.

In another embodiment, a test cartridge assembly for facilitating realtime detection of an infectious agent in a biological sample isdescribed. The test cartridge assembly includes a reservoir card and atest cartridge base. The reservoir card initially stores at least onereagent for testing a sample for an infectious agent. The reservoir cardis configured to interface with a test cartridge base through at leastone fluid port. The test cartridge base includes a reaction chamber anda fluid displacement mechanism. The reaction chamber receives the sampleand the at least one reagent, and has a predetermined internal geometryand at least one inner surface. The fluid displacement mechanismincludes a plunger for displacing the at least one reagent from thereservoir card into the reaction chamber through the at least one fluidport. When the at least one reagent is mixed with the sample in thereaction chamber a detectable signal is emitted if the infectious agentis present in the sample.

In yet another embodiment, a testing device for real time detection ofan infectious agent in a biological sample is described. A housing ofthe testing device includes a lid and an input/output device. Ananalysis portion includes a recess in the housing for accepting a testcartridge containing a sample to be tested. An actuator interacts withthe test cartridge when the lid is closed. The actuator causes at leastone reagent in the test cartridge to be displaced to react with thesample during the performance of a test. A sensor is associated with therecess in the housing to detect a signal emitted after the at least onereagent has been displaced by the actuator to react with the sample andto generate an output signal. A control unit is configured to receive aninput from a user via the input/output device to initiate a test. Inresponse to receiving the user input, the control unit actuates theactuator to displace the at least one reagent in the test cartridge toreact with the sample. The control unit receives the output signal fromthe sensor and outputs a test result to the user on the input/outputdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofpreferred embodiments of the invention, will be better understood whenread in conjunction with the appended drawings. For the purpose ofillustrating the invention, there are shown in the drawings embodimentswhich are presently preferred. It should be understood, however, thatthe invention is not limited to the precise arrangements andinstrumentalities shown. In the drawings:

FIG. 1A is a rear perspective view of a testing device with a closedhinged lid for detecting infectious agents according to a preferredembodiment of the present invention;

FIG. 1B is a front perspective view of the testing device of FIG. 1Awith the hinged lid open to show a cartridge recess;

FIG. 1C is a front perspective view of the testing device of FIGS. 1Aand 1B showing a test cartridge inserted into the cartridge recess;

FIG. 2A is an exploded front perspective view of the components of ananalysis portion of the testing device of FIG. 1 according to thepreferred embodiment of the present invention;

FIG. 2B is a front perspective view of the analysis portion of thetesting device of FIG. 2A;

FIG. 3A is a front perspective view of a test cartridge assemblycomprising a reservoir card inserted into a test cartridge base with abase lid closed for use with the testing device of FIG. 1 according tothe preferred embodiment of the present invention;

FIG. 3B is a front perspective view of the test cartridge assembly ofFIG. 3A with the test cartridge base lid open;

FIG. 3C is a bottom perspective view of the test cartridge assembly ofFIGS. 3A and 3B;

FIG. 4A is a front perspective view of the test cartridge base with thebase lid open of the test cartridge assembly of FIG. 3B according to thepreferred embodiment of the present invention;

FIG. 4B is an exploded front perspective view of the components of thetest cartridge base of FIG. 4A;

FIG. 5A is a front perspective view of the reservoir card in an initialarrangement for use in the test cartridge assembly of FIG. 3A accordingto the preferred embodiment of the present invention;

FIG. 5B is an exploded front perspective view of the components of thereservoir card of FIG. 5A;

FIG. 5C is a front perspective view of the reservoir card of FIG. 5A inan inserted arrangement to reveal fluid ports;

FIG. 6A is a magnified side elevational view of a portion of thereservoir card in the initial arrangement of FIG. 5A with a folded-overfilm covering the fluid ports;

FIG. 6B is a magnified side elevational view of the portion of thereservoir card in the inserted arrangement of FIG. 5C with thefolded-over film retracted;

FIG. 7 is a magnified cross-sectional side elevational view of a portionof the test cartridge assembly of FIG. 3A;

FIG. 8 is a cross-sectional side elevational view of the test cartridgeassembly of FIG. 3A;

FIG. 9 is a cross-sectional side elevational view of the test cartridgeassembly of FIG. 3A inserted into the analysis portion of the testingdevice of FIG. 2B;

FIG. 10A is a cross-sectional side elevational view of the testcartridge assembly of FIG. 3A with a plunger in an initial position;

FIG. 10B is a cross-sectional side elevational view of the testcartridge assembly of FIG. 3A with a plunger in a second position;

FIG. 10C is a cross-sectional side elevational view of the testcartridge assembly of FIG. 3A with a plunger in a final position;

FIG. 11 is a schematic block diagram of the electrical components of thetesting device of FIG. 1 according to the preferred embodiment of thepresent invention;

FIG. 12 is a schematic block diagram of a light sensing circuit of thetesting device of FIG. 1 according to the preferred embodiment of thepresent invention;

FIGS. 13A and 13B are a flowchart of steps of a control application ofthe testing device of FIG. 1 according to the preferred embodiment ofthe present invention;

FIG. 14 is an exemplary graphical user interface of a home screenprovided by the control application of FIGS. 13A and 13B;

FIG. 15 is an exemplary graphical user interface showing a test resultprovided by the control application of FIGS. 13A and 13B;

FIG. 16 is a flowchart of steps in which the test cartridge assembly 300is utilized in conjunction with the testing device 100 for performing atest; and

FIG. 17 is a chart illustrating the effectiveness of the system of thepresent invention with regard to detecting the presence of one or moreinfectious agents in a biological sample.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “right,” “left,” “lower” and “upper”designate directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” refer to directions toward and awayfrom, respectively, the geometric center of the stated component anddesignated parts thereof. Additionally, the words “a” and “an”, as usedin the claims and in the corresponding portions of the specification,mean “at least one.” The terminology includes the words abovespecifically mentioned, derivatives thereof and words of similar import.

The present invention provides a portable, self-contained system forrapidly (i.e., within one to five minutes or more) detecting infectiousagents, particularly pathogens in biological samples, particularlysamples derived from beef, pork, or other meat, poultry, fish, orvegetable matter, although other biological materials, such ashealthcare instruments and hospital surfaces, may be analyzed using thepresent invention. This system provides very high sensitivity (e.g., toa single cell of a particular infectious agent) without the need toculture infectious agents, such as bacteria, obtained from samples priorto testing. In an exemplary embodiment, the specific infectious agent isEscherichia coli, although other infectious agents (such as Salmonella,Listeria, and Campylobacter), toxins, and various contaminants may bedetected with the present invention. Escherichia coli O157 H7, O26, O45,O103, O111, O121, and O145, in either separate assays or multiplexedassays, may all be detected using this invention.

Referring to the drawings in detail, wherein like reference numbersrefer to like elements throughout the several figures, a portable,self-contained testing device 100 for performing a variety of real-time(or near real-time) qualitative tests to rapidly detect the presence ofinfectious agents in biological samples such as food and othersubstances is shown. Referring to FIGS. 1A-1C, the testing device 100for performing a rapid (real time or near real time) analysis of asample 414 (FIG. 4B) to identify infectious agents according to apreferred embodiment of the present invention is shown. In a preferredembodiment, the testing device 100 utilizes a disposable test cartridgeassembly 300 to test for specific analytes in a qualitative manner. Thetesting device 100 is a portable analyzer that interacts with the testcartridge assembly 300 and provides simple prompts for a user to obtainresults for specific tests that are designed to find offending analytesfrom a variety of sources. The test cartridge assembly 300, whichinteracts with the device, contains a living biosensor, which isengineered to detect and report an offending analyte in a sample 414.Samples 414 to be tested include materials such as food, liquids,surfaces, and the like which may be sources of infectious agents.Infectious agents include food borne illnesses, pathogens, viruses,bacteria, and the like. The testing device 100 allows for rapid analysisof the sample 414 to be performed without the time-consuming need toenrich or culture the materials being tested to facilitate the test.

FIG. 1A is a front perspective view of a testing device 100 with aclosed hinged lid 104 in accordance with a preferred embodiment of thepresent invention. The testing device 100 includes an outer housing 102which is preferably formed of a generally rigid, preferably polymericmaterial, such as acrylonitrile butadiene styrene. Other materials, orcombinations of materials, may be used to form the outer housing 102without departing from the scope of this disclosure. Such materials arewell known to those skilled in the art.

The testing device 100 includes an ON/OFF power switch 108, and a touchscreen liquid crystal display (“LCD”) 110 screen for permitting a userto interact with the testing device 100 when the power switch 108 is inthe ON position. The touch screen LCD 110 allows the user to providecommands to the testing device 100, and provides instructions to theuser by displaying menus to facilitate operation of the testing device100, as shown in FIGS. 14 and 15. As will be discussed further, themenus include, but are not limited to, graphical user interfaces forproviding information and/or data to the user concerning the status orresults of a specific test or operation being performed by the testingdevice 100.

In a preferred embodiment, the touch screen LCD 110 comprises an LCDunit and an overlaid touch screen capable of receiving a user's inputthrough a latex glove, or the like. In the present embodiment, the LCD110 comprises a five (5) inch diagonal QVGA, IPS-based TFT LCD moduleVL-PS-COG-T500F2080-X1 from VARITRONIX, and a glass-film-glass resistivetouch screen model AD-5.0-4RU-02-200 from AD METRO. Other models andmanufacturers of the touch screen LCD 110 may be utilized withoutdeparting from the scope of this invention. Furthermore, other sizes andtypes of input/output devices, such as buttons, keyboards, track pads,and the like, may be employed in the testing device 100 withoutdeparting from the scope of this invention.

The testing device 100 includes a plurality of interface ports 112, suchas an Ethernet port 112 a, and a micro USB port 112 b. The interfaceports 112 allow the testing device 100 to interface, download, andupload data (e.g., test data), to or from a local or remotely locatedcomputing device, mobile device, server, or the like (not shown). Thestructure and operation of typical interface ports 112 are well known tothose skilled in the art, and are not described in detail herein for thesake of brevity. While particular interface ports 112 have beendescribed herein, other ports and other methods of wired and/or wirelesscommunication, such as 802.11 Wi-Fi, may be integrated and utilized inthe testing device 100 without departing from the scope of thisinvention.

Referring to FIG. 11, the external housing 102 of the testing device 100also contains a power supply system 1126 and other electrical andelectronic components, circuitry and software necessary to permit thetesting device 100 to perform testing upon an installed test cartridgeassembly 300. Preferably, the power supply system 1126 comprises one ormore batteries 116 to facilitate stand-alone operation of the testingdevice 100. A battery charger connector 114 (FIG. 1A) is also providedto charge the one or more batteries 116, which are preferablyrechargeable.

The one or more batteries 116 are each preferably comprised of adouble-cell lithium ion battery, model 503759AY from AUTEC BATTERY, with2200 mAh capacity at 3.7 volts nominally. The power supply system 1126also includes an intelligent fast charge battery charging circuit 1114which functions to recharge the batteries 116 and monitors the batterytemperature using a temperature sensor embedded within the batteries116. In the present embodiment, the battery charging circuit 1114 is aTEXAS INSTRUMENTS model BQ240032ARHLR. If the temperature of thebatteries 116 is not within safe operating range, the battery chargingcircuit 1114 stops the charging of the batteries 116 until a safetemperature is reached. The battery charger is activated whenever anaccompanying AC adapter (not shown) is connected to the testing device100 through the battery charger connector 114 to provide power to thetesting device 100 and permit normal use of the testing device 100during the recharging of the batteries 116

Referring to FIG. 1B, the testing device 100 of FIG. 1A is shown withits hinged lid 104 in an open position to reveal a cartridge recess 152.The cartridge recess 152 is preferably only accessible to a user whenthe hinged lid 104 is in the open position. As shown in FIG. 1A, thecartridge recess 152 is covered by the hinged lid 104 when the hingedline 104 is in its closed position. The hinged lid 104 is released by amechanical actuator 106, preferably located on the outer housing 102,proximate to the hinged lid 104. The mechanical actuator 106, which ispreferably a button, switch, or the like, releases the hinged lid 104 torotate from the closed position, which is substantially integrated withthe outer housing 102 as shown in FIG. 1A, to an open position, which isaway from the outer housing 102, as shown in FIG. 1B. Referring to FIg.1C, when the hinged lid 104 is in the open position, a test cartridgeassembly 300 may be introduced into the cartridge recess 152.

As shown in FIGS. 1B and 1C, the hinged lid 104 contains two lidprotrusions 104 a that are arranged to retain the hinged lid 104 in theclosed position while a test is being performed by the testing device100. In the closed position, the lid protrusions 104 a are engaged by apair of locking latches 104 b contained within outer housing 102. Thelocking latches 104 b are disengaged from the lid protrusions 104 a bythe user depressing the mechanical actuator 106. The hinged lid 104preferably includes a light-sealing groove 118 having a light sealinggasket therein (not shown) which engages with a light sealing rib 120 inthe analysis portion frame 202 (FIG. 2B) surrounding the cartridgerecess 152 when the hinged lid 104 is in the closed position to preventambient light from entering the cartridge recess 152. A generally squareprojection 122 with tapered sidewalls on the interior surface of thehinged lid 104 engages with tapered sidewalls 204A of an analysisportion 200 housing 204 when the hinged lid 104 is in the closedposition.

Referring now to FIGS. 2A and 2B, an analysis portion 200 of the testingdevice 100 according to the preferred embodiment of this invention isshown. The analysis portion 200 includes an analysis portion frame 202that is contained within the outer housing 102. The analysis portionframe 202 is preferably arranged in a predetermined structure andorientation, having a first end 202 a and a second end 202 b tofacilitate acceptance of a test cartridge assembly 300 (FIG. 1C), orother compatible testing container. An analysis portion housing 204,defining the cartridge recess 152, is positioned at a first end 202 a ofthe analysis portion frame 202. As shown in FIG. 1C, the cartridgerecess 152 allows a user to introduce a test cartridge assembly 300 intothe analysis portion 200 of the testing device 100 when the hinged lid104 is in the open position. The analysis portion housing 204 functionsas the interface between the testing device 100 and the test cartridgeassembly 300. As will hereinafter become apparent, the disposable testcartridge assembly 300 is employed for collecting and introducing a testsample 414 (FIG. 4B) into the testing device 100 for the purpose ofperforming one or more tests on the test sample 414.

The analysis portion housing 204 of the analysis portion 200 will now bedescribed in further detail. The analysis portion housing 204 ispreferably made of a generally rigid, polymeric material such asacrylonitrile butadiene styrene or some other such polymeric materialwell known to those skilled in the art, and is located within theanalysis portion frame 202. The analysis portion frame 202 providesstructural support to the analysis portion housing 204, and is the maincomponent in a light sealing scheme which greatly minimizes or preventsambient light from entering the cartridge recess 152 by way of therectangular walls that surround the analysis portion frame 202, therebypreventing environmental light emissions from reaching a sensor 206. Ina preferred embodiment, the sensor 206 is a light sensor.

The testing device 100 performs a desired test upon a sample 414retrieved from a variety of sources by analyzing the electrical outputof the sensor 206. When the sensor 206 is a light sensor, the outputvaries with the amount of light incident on the sensing surface 206 a ofthe light sensor 206 having originated within the test cartridgeassembly 300. Based on the type of test being performed, the output ofthe light sensor 206 determines whether the analyzed sample 414 ispositive or negative for the presence of the material (infectious agent)that is being sought in a qualitative analysis. That is, there need notbe a determination by the testing device 100 of the actual amount of thematerial present in the test sample 414. The testing device 100 iscapable of changing parameters for testing based on the test performedand the test cartridge assemblies 300 employed.

Since in the preferred embodiment, evaluation of the material within thetest cartridge assembly 300 by the testing device 100 requires detectingthe presence of light that may be emitted from the test sample 414introduced by the test cartridge assembly 300, it is preferable tominimize or eliminate the amount of external or ambient light beingintroduced into the cartridge recess 152 of the testing device 100during testing. To achieve this goal, the analysis portion 200preferably prevents most or all environmental light emissions fromreaching the sensor 206. The sensor 206 is arranged on a printed circuitboard (“PCB”) 208, which is positioned under the analysis portionhousing 204. Minimizing such environmental light emissions from reachingthe sensor 206 prevents an erroneous output from the sensor 206.

The analysis portion frame 202 and the hinged lid 104 are preferablymade of a generally rigid, opaque solid material such as aluminum inorder to reflect or absorb all measureable light incident on thematerial, or some other such opaque solid material well known to thoseof ordinary skill in the art. The base 204B of the analysis portionhousing 204 contains a rectangular cutout 214 on a lower surface. Aviewing window 216 is mounted in the rectangular cutout 214. The viewingwindow 216 is preferably made of an optics grade transparent solidmaterial, such as quartz glass or another transparent solid material, asis well known to those skilled in the art. The sensor 206 is positionedbeneath the viewing window 216, allowing light to pass from the testcartridge assembly 300 through the viewing window 216 to the sensor 206with a minimal amount of light absorption or reflection. Therefore, thesensor 206 receives the maximum signal possible through the viewingwindow 216.

In the preferred embodiment, the sensor 206 is a light sensor, and evenmore preferably the sensor 206 is a photomultiplier tube (PMT), as willbe described further with reference to FIG. 12. The PCB 208 furtherincludes an RFID communications circuit 210, a high voltage power supply218 for use with the sensor 206, and other light sensing circuitry 1200,as will be described further below with reference to FIG. 12.Preferably, the RFID communications circuit 210 is positioned beneath anarea of the cartridge recess 152 that aligns with an RFID tag 508 (FIG.5B) within the test cartridge assembly 300 when the test cartridgeassembly 300 is introduced into the cartridge recess 152.

A sensor shield 220 is positioned to substantially surround the sensor206. The sensor shield 220 isolates the sensor 206 from electromagneticand magnetic interference. The sensor shield 220 is preferably made froma generally rigid, solid conductive material with high magneticpermeability such as mu-metal or another such solid conductive material,as is well known to those skilled in the art. One of the walls of theanalysis portion housing 204 contains a hollow protrusion 222 extendinginto the cartridge recess 152, which mates with a recess in the testcartridge assembly 300. The hollow protrusion 222 allows a piston 224and piston rod 224A, which engages a fluid displacement mechanism 900(FIG. 9) in the test cartridge assembly 300, to pass therethrough andcontact with a plunger 424 (FIG. 4B) of the test cartridge assembly 300.

The piston 224 is preferably made of a generally rigid, polymericmaterial such as polystyrene or another similar polymeric material, asis well known to those skilled in the art. The piston 224 is actuated bya motor 226. In the preferred embodiment, the motor 226 is a linearstepper motor. However, other actuators, such as pneumatic pistons,servos, or the like may be used without departing from the scope of thisinvention. The piston 224 is engaged to the motor 226 via a threadedshaft 226A on the motor 226 coupled to an integral threaded hole (notshown) within the piston 224. In the currently preferred embodiment, themotor 226 is a HAYDON-KERK model 19542-05-905 stepper motor. In order toreduce the introduction of noise from the motor 226 into the analysisportion 200, the motor 226 is located outside of the analysis portionhousing 204, not in close proximity to the sensor 206. This arrangementof the motor 226 relative to the sensor 206 decreases the possibility ofthe motor 226 electrically or electromagnetically interfering with thesensor 206.

A projection 228 protrudes from the piston 224, and aligns with aposition detector 230, which is positioned outside of the analysisportion 200. At a certain stage of travel of the piston 224 (describedbelow), the projection 228 triggers the position detector 230 togenerate a position signal. In one embodiment, the position detector 230trigger position corresponds with the second position of the plunger 424shown in FIG. 10B. However, the trigger position may alternatelycorrespond with the final position of the plunger 424, shown in FIG.10C, or any other position in the path of the plunger 424. In apreferred embodiment, the position detector 230 is a photo-interrupterand the position detector 230 is triggered by the projection 228blocking the path of light within the position detector 230, at whichtime, a signal is sent to the microprocessor 1102 to indicate theposition of the piston 224. In this way, precision sensing of theposition of the piston 224 can occur to ensure that there are no errorsin the actuation of the test cartridge assembly 300. In the preferredembodiment, the position detector 230 is an OMRON model EE-SX4134photo-interrupter. However, it will be appreciated by those skilled inthe art that other types of devices may be utilized for the positiondetector 230 without departing from the scope of this invention.

The piston 224 includes a piston rod 224A extending therefrom whichcontains spaced pairs of radially outwardly extending annular flanges232A-C in spaced locations along its length. Compressible sliding seals234A and 234B are radially mounted between the annular flanges 232A and232C, respectively. The sliding seals 234 are preferably made of anelastomeric material such as silicone, or some other such elastomericmaterial, as is well known to those skilled in the art. When the piston224 is installed, the first sliding seal 234A, mounted between annularflanges 232A engages with the interior surface of the hollow protrusion222 of the analysis portion housing 204 to create a fluid-tight sealthat prevents liquids from entering into the lower analysis portion 200,from the cartridge recess 152, and reaching the electronic components onthe PCB 208 beneath the analysis portion housing 204. The second slidingseal 234B, mounted between annular flanges 232C engages with theinterior surface of a hollow channel through which the piston rod 224Apasses into the analysis portion frame 202 to create a light-tight sealthat prevents environmental (ambient) light emissions from entering thelight sealed area of the analysis portion housing 204 along the path ofthe piston 224.

The piston rod 224A also contains a third pair of annular flanges 232Bwhich engage a sliding shutter 236. The sliding shutter 236 ispreferably constructed of a rigid, opaque, thin material, such as aformed stainless steel sheet, for the purpose of keeping the analysisportion 200 low profile and sized to be portable. Alternately, thesliding shutter 236 may be constructed of a conductive material withhigh magnetic permeability, such as a mu metal in order to provideadditional shielding to the sensor 206. When initially engaged by thepiston rod 224A, the sliding shutter 236 passes between the sensor 206and the viewing window 216. In this position, the sliding shutter 236reflects or absorbs nearly all environmental light emissions that wouldotherwise reach the sensor 206 when the hinged lid 104 is open and theanalysis portion 200 is exposed to ambient light. In the case that thesensor 206 is a PMT, the sliding shutter 236 protects the sensor 206,which is vulnerable to saturation and damage when fully exposed toambient light levels. The sliding shutter 236 contains an aperture 238that aligns with the sensor 206 at the start of a test. Preferably,prior to the beginning of a test, the sliding shutter 236 covers thesensor 206. It is desirable for the sliding shutter 236 to engage thepiston rod 224A and make use of the motion of the motor 226 to slideinto the position in which the aperture 238 is over the sensor 206 atthe start of a test. This arrangement minimizes additional componentcosts, and further reduces the risk of electrical or electromagneticinterference.

Referring now to FIGS. 1 and 2, the analysis portion 200 is locatedwithin the housing 102 of the testing device 100. At least a portion ofthe analysis portion 200 is at least partially covered by the hinged lid104 when the hinged lid 104 is in the closed position shown in FIG. 1A.The analysis portion 200 preferably includes the PCB 208 having theintegral RFID communications circuit 210 that is configured tocommunicate via radio frequency with a unique Radio FrequencyIdentification (“RFID”) tag 508 of a test cartridge assembly 300 (FIG.3). In the preferred embodiment, the RFID communications circuit 210 isa TEXAS INSTRUMENTS RFID communications IC model TRF7961. However, itwill be apparent to those skilled in the art that other types ofscanners or scanning devices, and other data transmission schemes, couldalternatively be employed for providing information to the testingdevice 100 and/or writing information to the RFID tag 508 of the testcartridge assembly 300.

It should be appreciated by those of ordinary skill in the art that theprecise structure of the analysis portion 200 and/or its components aremerely that of a currently preferred embodiment and that variations maybe made to the structure of the analysis portion 200 and/or itscomponents without departing from the scope and spirit of the invention.Thus, the present invention is not limited to the precise structure ofthe analysis portion 200 described herein, but is intended to encompassstructural and/or operational variations, as well as other structuresand arrangements which may perform the same, or substantially the samefunctions, as those of the current analysis portion 200.

The variations may include such structural changes as omitting anelectromechanical motor, and instead relying on a user input force toactuate of the cartridge, actuating the test cartridge directly withoutthe use of a piston, utilizing multiple motors for different actions,placing the motor within the light-sealed area of the analysis portion200, or controlling the motor without precise position sensing. Further,the shape, arrangement and size of the test cartridge recess 152 in theanalysis portion housing 204, the lid protrusions 104 a, and lockinglatches 104 b may vary from what is shown and described herein withoutdeparting from the scope of this invention. All that is necessary isthat the cartridge recess 152 must compliment and conform to the sizeand shape of the test cartridge assembly 300 such that the cartridgerecess 152 may accept an introduced test cartridge assembly 300.

Similarly, light sensing by the sensor 206 may be replaced by adifferent signal detection scheme, as is well known to those skilled inthe art, without departing from the scope of this invention. Forexample, detection of electrical signals could be employed forevaluation of the test result. In this case, it may be preferable tominimize or eliminate extraneous sources of noise other than light.Structural changes to the analysis portion 200 that facilitate theminimizing or eliminating such extraneous sources of noise other thanlight are within the scope of this invention.

Referring now to FIGS. 3A and 3B, there is shown the test cartridgeassembly 300 for use with the testing device 100 according to thepreferred embodiment of the present invention. Preferably, the testcartridge assembly 300 is a single-use, disposable cartridge that isemployed for receiving a small quantity of a sample 414 (FIG. 4B)gathered from foodstuffs or other sources for a test to be performed bythe testing device 100. Therefore, the test cartridge assembly 300 ispreferably configured to be fixedly insertable into the testing device100 for the duration of a performance of a selected test. Even morepreferably, each test cartridge assembly 300 contains all the necessaryreagents 504, 506 (FIG. 5B) and the like for the performance of a singletest, as will be described further herein.

As shown in FIG. 3A, the test cartridge assembly 300 preferablycomprises two separate portions, a test cartridge base 400, describedfurther with reference to FIG. 4, and a reservoir card 500, describedfurther with reference to FIG. 5. The test cartridge base 400 and thereservoir card 500 are configured to interact with one another for theperformance of a test by the testing device 100. The reservoir card 500is designed as a separate part from the test cartridge base 400 in orderto occupy a minimal volume, and to achieve a high packing density.Packing density is a critical consideration for the occasions when thenecessary reagents 504, 506 require storage at low or below freezingtemperatures. However, an integrated, single unit, test cartridgeassembly 300 may similarly be produced, and is within the scope of thisdisclosure.

The test cartridge base 400 is configured to accept the separatereservoir card 500 in a slot 402 (FIG. 4A) at a first end 400 a of thetest cartridge base 400. The reservoir card 500 is specifically designedto provide a convenient, small sized storage and delivery vehicle forone or more biosensors (reagents 504, 506). As shown in FIGS. 3A and 3B,a user assembles the reservoir card 500 into the test cartridge base 400by sliding the reservoir card 500 into the slot 402. Once the reservoircard 500 is inserted into the test cartridge base 400, the reservoircard 500 is fixedly attached to the test cartridge base 400. Thepermanent attachment features 502 prevent misuse of the test cartridgebase 400, such as reuse of the test cartridge base 400 with multiplereservoir cards 500. Contamination of the test cartridge base 400 and/orreservoir card 500 is thereby avoided. The reservoir card 500 may beattached to the test cartridge base 400 using any known suitablemechanical attachment device or member, such as the one way attachmentfeatures 502 (FIG. 5B).

The test cartridge base 400 preferably does not contain anytest-specialized components, and may therefore be common to a pluralityof test types. As such, the test cartridge base 400 should be compatiblewith multiple types of reservoir cards 500. As shown in FIGS. 4B and 9,the test cartridge base 400 contains a reaction chamber 404 and a fluiddisplacement mechanism 900, which together occupy a relatively largevolume in comparison to the volume of the reservoir card 500. Referringto FIGS. 5A and 5B, the reservoir card 500 contains all of the necessaryreagents 504, 506, and the like, for performing a single test by thetesting device 100. Accordingly, a plurality of distinct types ofreservoir cards 500, each having one or more distinct reagents 504, 506for performing a particular test type, may be provided. Preferably, thereaction chamber 404 facilitates a proper mixture of the sample 414 andthe reagents 504, 506, while minimizing damage to the living cells whichcomprise the reagents 504, 506. The reaction chamber 404 also maximizesgathering the light that the reagents 504, 506 emits to the sensor 206in the presence of an offensive analyte or to confirm the properfunctioning of the first phase of the test.

As best shown in FIG. 4B, the test cartridge base 400 is comprised of agenerally rectangular housing 401 with an integral hinged lid 408. Therectangular housing 401 is preferably formed of a generally rigid,preferably polymeric material, such as polypropylene or another suchpolymeric material well-known to those skilled in the art. Anadhesive-backed film 410 is used to enclose fluid channels 406 formed inthe planar surface 400 b of the housing 401 for the sealed passage ofreagents 504, 506 and/or air between the reservoir card 500 and the testcartridge base 400. The test cartridge base 400 housing 401 alsoincludes an integral reaction chamber 404 for deposition of the sample414, and eventual mixing of the sample 414 with the reagents 504, 506for performing the desired test.

When the test cartridge assembly 300 is placed in the cartridge recess152, the bottom surface 404 a of the reaction chamber 404 within thetest cartridge base 400 housing 401 is aligned with the light sensor206. Referring to FIG. 3C, the reaction chamber 404 is sealed on thebottom surface with a lens 412. The lens 412 is preferably formed of arigid, preferably polymeric material such as polycarbonate or some othersuch polymeric material well-known to those skilled in the art. The lens412 material is preferably an optics grade transparent material in orderto prevent unwanted light absorption or reflection between the reagents504, 506 and the light sensor 206. In the preferred embodiment, the lens412 is thermally welded to the test cartridge base 400 housing 401 inorder to provide a liquid-tight seal and minimize the introduction ofcontaminants into the reaction chamber 404. Referring to FIGS. 4A and4B, the reaction chamber 404 is open to the top surface 400 b of thetest cartridge base 400 housing 401 in order to allow a user to directlydeposit the sample 414 (preferably in liquid form) into the reactionchamber 404.

The adhesive-backed film 410 is placed on the top surface 400 b of thetest cartridge base 400 housing 401. The film 410 is preferablypre-scored or perforated 416 above the reaction chamber 404 in a waythat allows the user to pierce through the film 410 using the tip of adeposition tool (not shown), such as a pipette for deposition of thesample 414 into the reaction chamber 404. The pre-scoring or perforation416 of the film 410 is desirable in order to provide a visual cue to theuser that they have completed the sample deposition step in the testprocess, or that the test cartridge assembly 300 was previously used andshould be discarded. A compressible gasket 418 with adhesive backing 418b is placed around the perimeter of the opening on the top surface 400 bto the reaction chamber 404 (surrounding the perforated or pre-scoredarea 416 of the adhesive backed film 410, see FIG. 4A). for the purposeof creating a fluid-tight seal when the integral test cartridge base 400hinged lid 408 is closed. The integral test cartridge base 400 hingedlid 408 contains snap features 408 a, 408 b to retain the test cartridgebase 400 hinged lid 408 in a closed position by interacting with catchslots 420 a, 420 b after the sample 414 has been deposited into thereaction chamber 404.

Still referring to FIGS. 4B and 3C, a central bore 422 is located withinthe test cartridge base 400 housing 401 that contains a plunger 424 aspart of the test cartridge's fluid displacement mechanism 900, whichwill hereinafter be described in greater detail. The plunger 424 ispreferably made of an elastomeric material, such as silicone rubber orsome other such elastomeric material, as is well-known to those skilledin the art and is sized to sealingly engage the interior wall of thecentral bore 422. The top surface 400 b of the test cartridge base 400housing 401 contains a relatively large vent overflow chamber 426 whichcommunicates with the reaction chamber 404 by a vent channel 426A. Thevent overflow chamber 426 is present to allow air to be displaced out ofthe reaction chamber 404 during the introduction of the reagents 504,506, and contains features to contain any stray amount of liquid thatmay enter the vent channel 426A. Preferably, the vent overflow chamber426 contains an absorbent material 428 utilizing an anti-microbialcoating that the vented air must pass through as it exits the testcartridge base 400 housing 401. This ensures that any stray amount ofliquid will be absorbed and contained within the vent overflow chamber426, and any biological components will be destroyed.

As shown in FIG. 5B, the reservoir card 500 includes a plurality offluid ports 516, which when the reservoir card 500 is inserted into thetest cartridge base 400 housing 401 interface with a series of sealingfeatures 702 (FIG. 7), thereby making connections with the reservoircard 500 when assembled. The sealing features 702 are recessed under awall 401A (FIG. 7) in the test cartridge base 400 housing 401 for thepurpose of preventing damage to the sealing features 702, andeliminating potential sites for easily contacted contaminants to beintroduced to the reagents 504, 506.

It should be appreciated by those skilled in the art that the precisestructure of the test cartridge base 400 and/or its components aremerely that of a preferred embodiment, and that variations may be madeto the structure of the test cartridge base 400 and/or its componentswithout departing from the scope and spirit of the invention. Otherstructural and functional variations, such as, depositing the sample 414in a location other than the reaction chamber 404 to be moved to thereaction chamber 404 at a later time, utilizing multiple parts toachieve the test cartridge base 400 housing 401, and reaction chamber404 features, using a separate lid or closure scheme for the reactionchamber 404 after sample deposition, or alternatively locating theplunger 424 and/or other components of the fluid displacement mechanism900 on the reservoir card 500 are all within the scope of thisinvention.

The reaction chamber 404 and fluid channels 406 that lead to thereaction chamber 404 within the test cartridge base 400 housing 401 arepreferably designed to achieve several objectives. An inlet channel 802(FIG. 8) for fluid entering the reaction chamber 404 is preferablytubular in shape with a diameter which is preferably small and tapers tobecome smaller at the inlet to the reaction chamber 404. This structurepreferably increases the velocity of fluids entering the reactionchamber 404 to promote vigorous, and therefore homogenous, mixing due tothe bulk motion of the of the reagents 504, 506 within the reactionchamber 404.

Referring to FIG. 8, a cross-sectional side elevational view of the testcartridge assembly 300 is shown. It is desirable to mix the reagents504, 506 and sample 414 in a way to promote mixing beyond moleculardiffusion, in order to minimize the duration of the test by ensuringthat any infectious agent present in the sample 414 rapidly encountersthe reagents 504 and 506. In the preferred embodiment, the minimumdiameter of the inlet channel 802 is 0.75 mm. The inlet channel 802 isfurther preferably offset from the central axis of the reaction chamber404 in order to promote a clockwise or counterclockwise rotationalmotion of the reagents 504 and 506 around the central axis of thereaction chamber 404 as the fluids are mixed in order to increase thehomogeneity of the mixture.

In the currently preferred embodiment, the inlet channel 802 isapproximately tangent to the interior surface of the reaction chamber404. This is desirable in order to allow the incoming fluid to travelfrom the inlet channel 802 to the fluid level within the reactionchamber 404 while remaining in contact with the side surface of thereaction chamber 404, which allows for a minimally turbulent flow andminimal introduction of air bubbles into the mixed fluids. Bubbles areundesirable due to the unpredictable refraction of light they cause aslight emitted by the reagents 504, 506 interacting with the sample 414travels through bubbles within the mixed reagents 504, 506 or on thesurface of the mixed reagents 504, 506.

In some embodiments of the invention, a stabilizer is included in thereaction chamber 404. The stabilizer may be, for example, Pluronic F68,which is used in cell cultures as a stabilizer of cell membranes byprotecting from membrane shearing and additionally as an anti-foamingagent. Certain embodiments of this invention also include at least oneadditive, such as Pluronic F68, polyethylene glycol, methocel, or thelike, located in the reaction chamber 404 for minimizing the formationof bubbles in the reaction chamber 404 during mixing of the sample 414and the reagents 504, 506. This additive may further include asurfactant, such as Pluronic F68, Polyvinyl pyrolidone, Polyethyleneglycol, Polyvinyl alcohol, Methocel (methyl cellulose), or the like.Some embodiments of the present invention also include a device fordisrupting individual cells of the sample 414 and particularly theinfectious agent within the sample 414 prior to mixing the sample 414with the reagents 504, 506 for purposes of amplifying the light signalgenerated by the reagents 504, 506 reacting with an infectious agentwithin the sample. An example of such a device is a sonicator (notshown).

The axis of the inlet channel 802 is preferably angled above horizontalin order to provide a partially downward direction to the incoming fluidflow to ensure that the reagents 504, 506 are mixed with the fluidresiding at the bottom of the reaction chamber 404. In the currentlypreferred embodiment, the inlet channel 802 is angled above horizontalat an angle of approximately thirty (30) degrees, and additionally theoptimum functional range occurs between fifteen (15) degrees and sixty(60) degrees above horizontal. It will be appreciated by those skilledin the art that the arrangement, position and structure of the inletchannel 802 may be varied without departing from the scope of thepresent invention.

Alternatively, if desired, the reagents 504, 506 may be introduced tothe reaction chamber 404 using alternative fluid delivery techniques,such as a vertical channel (not shown) that delivers the reagents 504,506 to the reaction chamber 404, or delivering the fluid reagents 504,506 directly on the central axis of the reaction chamber 404 in order tocreate a column of reagent flowing into the reaction chamber 404promoting mixing through entrainment. Furthermore, a user may deliverthe one or more reagents 504, 506 manually in the same way and, forexample, at the same time as the sample 414 is deposited into thereaction chamber 404.

The reaction chamber 404 preferably has a shape that maximizes theamount of photons that are reflected toward the bottom of the reactionchamber 404 to allow the photons to be read by the sensor 206 positionedunder the reaction chamber 404 in the analysis portion 200. In thepreferred embodiment, the shape of the reaction chamber 404 is arevolved section to facilitate the clockwise or counterclockwise motionof the mixing fluids 414, 504, 506 around the central axis of thereaction chamber 404. Alternatively, if desired, a reaction chamber 404shape other than a revolved section, such as a rectangular or irregularshape, could be used. In the preferred embodiment, the revolved sectionused to form the reaction chamber 404 is a portion of an ellipse. Thiselliptical shape is desirable in order to aid in collecting stray lightemitted by the reagents 504, 506 reacting with the sample 414 andreflecting this light toward the surface of the light sensor 206. Thereaction chamber 404 shape is preferably generally parabolic. Thereaction chamber 404 may be a revolved half of an ellipse with anopening at the top of approximately 2.5 mm, and with the lower diameterlocated at the major or minor axis of the ellipse and equal toapproximately 8 mm.

The surface of the reaction chamber 404 is preferably reflective, inorder to further enhance the light collection properties of theelliptical shape. In the preferred embodiment, the maximum diameter ofthe sensing surface 206 a of the sensor 206 is limited in order toachieve the maximum signal to noise ratio of the output of the lightsensing circuit 1200 (FIG. 12). The diameter of at least the bottom ofthe reaction chamber 404 is designed to approximately match the diameterof the sensor 206, which influences the elliptical shape that can beachieved in a reaction chamber 404 designed to hold a specific volume offluids for a given test type. In the preferred embodiment, thepreferable reaction chamber 404 surface color is a partially diffusingwhite, due to the additional light collection that occurs when lightthat would not otherwise be reflected directly to the sensor 206 surface206 a is partially diffused by the white surface and a fraction of thelight is directed toward the sensor 206 surface 206 a. Alternatively,other surface finishes, colors, and materials such as a near-mirrorfinish aluminum, or a transparent material could be used.

It is desirable for the reaction chamber 404 material to be minimallyphosphorescent in order to prevent light emitted from the reactionchamber 404 itself from overwhelming any emitted light from the reagents504, 506 reacting with the sample 414 and thereby preventing orotherwise affecting detection. Although white polymeric materials suchas acrylonitrile butadiene styrene or other such polymeric materialshave been found to exhibit a low level of phosphorescence, theadditional light collection provided by the combination of lightreflection and diffusion has been found to be a benefit to the signal tonoise ratio of the output of the light sensing circuit 1200.

As shown in FIGS. 5A-5C, the reservoir card 500 is comprised of agenerally rectangular housing 501. The reservoir card 500 housing 501 ispreferably formed of a generally rigid, preferably polymeric materialsuch as polypropylene or some other such polymeric material well-knownto those skilled in the art. Referring to FIG. 5B, fluid storagechannels 510, 512 are formed into the upper surface 501 a of thereservoir card 500 housing 501 in order to provide storage for all ofthe necessary reagents 504, 506 for performing a specific test type.

In the preferred embodiment, the first reagent 504 is a biosensorreagent capable of emitting light when a specific pathogen or set ofpathogens is detected, and the second reagent 506 is a positive controlsample, such as anti-Immunoglobulin M (anti-IgM) or digitonin. Thesecond reagent 506 is utilized for the purpose of rapid activation ofthe first biosensor reagent 504 after the duration of the initial testas a verification of the viability of the biosensor reagent 504. Thesecond reagent 506 functions as a negative result control test, and istherefore optional. That is, the test may be performed without thepresence and/or use of the second reagent 506, but in its absence, theaccuracy of the test result may be difficult to verify.

The fluid storage channels 510, 512 for storing the reagents 504, 506are formed to provide a small cross-sectional area, preferably ofapproximately 1 mm width and 1 mm height. The small cross-sectional areaallows the stored reagents 504, 506 to be easily displaced out of thefluid storage channels 510, 512 using one or more additional fluids,such as air. A smaller cross-sectional area is also desirable due to theresulting decrease in thawing time in the occasions where the necessaryreagents 504, 506 are required to be stored frozen and are thawedimmediately before testing. A thin cover 514, preferably of a polymericmaterial or the like, is bonded to the reservoir card 500 housing 501 toenclose the fluid storage channels 510, 512 and provide a fluid-tightseal on the top surface 501 a of the reservoir card 500 housing 501.

Referring to FIG. 5B, the reservoir card 500 housing 501 also contains arecessed area (not shown) on the bottom surface 501 b to contain theRFID tag 508. The recessed area serves to prevent damage from accidentalcontact with sensitive components of the RFID tag 508. The RFID tag 508is located within or is secured to the reservoir card 500 in order tominimize user error in associating test cartridge data 300 stored on theRFID tag 508 with the necessary reagents 504, 506 required for specifictest types. Use of RFID technology is preferable in order to automatethe data transfer between the test cartridge assembly 300 and thetesting device 100, thereby minimizing sources of possible user error.

An end face 501 c of the reservoir card 500 housing 501 contains aplurality of fluid ports 516 a-516 d, which make fluid connections withthe test cartridge base 400 housing 401, when assembled into the testcartridge assembly 300. Each of the fluid ports 516 are attached to acompressible gasket 518 with an adhesive backing or the like around theperimeter of each fluid port 516. The compressible gaskets 518 create afluid-tight seal with the test cartridge base 400 housing 401 when thereservoir card 500 is properly installed in the test cartridge base 400as shown.

In order to prevent contaminants from contacting the fluid ports 516,and to prevent damage to the compressible gaskets 518, the end face 501c of the reservoir card 500 housing 501 is initially covered with a film520 (see FIG. 5A). In the preferred embodiment, the film 520 is aPolyethylene terephthalate film, or some other flexible polymeric filmcapable of creating a liquid tight seal with the reservoir card 500housing 501. The film 520 has selectively applied adhesive backing, andis selectively bonded using the adhesive on a single side of the film520 to the reservoir card 500 housing 501 in a way such that each fluidport 516 is individually sealed around its perimeter, and one end 520 aof the film 520 is permanently bonded to the top face 501 a of thereservoir card 500.

FIG. 6A is a magnified side elevational view of a portion of thereservoir card 500 in the initial arrangement of FIG. 5A with afolded-over film 520 covering the fluid ports 516. As shown in FIGS. 5Band 6A, the film 520 is laid back upon itself at point 520 b so that theremaining end of the film 520 is directed back to the top face 501 a ofthe reservoir card 500. The remaining end 520 c of the film 520 ispermanently bonded utilizing the selectively applied adhesive to acarrier part 522. The carrier part 522 is preferably made of a generallyrigid, polymeric material such as polypropylene, or another suchpolymeric material known to those skilled in the art.

FIG. 6B is a magnified side elevational view of the portion of thereservoir card 500 in the inserted arrangement of FIG. 5C with thefolded-over film 520 retracted to reveal the fluid ports 516. As shownin FIG. 6B, any motion of the carrier part 522 away from the fluid ports516 results in a peeling motion of the bonded film 520 from the fluidport end 501 c of the reservoir card 500 housing 501 which unseals andexposes the fluid ports 516 and their gaskets 518.

There are several actions that occur as the reservoir card 500 isassembled into the test cartridge base 400. As the reservoir card 500 isslid into the receiving slot 402 on the test cartridge base 400 housing401, the carrier part 522 on the reservoir card 500 mechanicallyinterferes with the top wall of the receiving slot 402 on the testcartridge base 400 housing 401. The reservoir card 500 is shaped so thatit cannot be fully inserted into the receiving slot 402 of the testcartridge base 400 in a backwards or top-side-down orientation. When thereservoir card 500 is in the correct orientation, as the user continuesto insert the reservoir card 500, the mechanical interference betweenthe carrier part 522 and test cartridge base 400 housing 401 wall causesthe carrier part 522 to move relative to the reservoir card 500 awayfrom the fluid ports 516 (See FIG. 5C).

As described above, the motion of the carrier part 522 away from thefluid ports 516 of the reservoir card 500 causes a peeling motion of thefilm 520 in place over the fluid ports 516 of the reservoir card 500.The peeling of the film 520 exposes the fluid ports 516 and theirgaskets 518 on the reservoir card 500 (See FIG. 5C). Preferably, thecomplete exposing of the fluid ports 516 occurs after the reservoir card500 has been fully engaged with the receiving slot 402 on the testcartridge base 400 housing 401 so that the fluid ports 516 are protectedby the top wall of the receiving slot and are never openly exposed tothe external environment. This behavior is desirable to preventcontaminants from contacting the fluid ports 516 and becoming introducedto the reagents 504, 506.

As the reservoir card 500 moves fully into the receiving slot 402 on thetest cartridge base 400 housing 401, referring to FIG. 7, sealingfeatures 702 present on the test cartridge base 400 housing 401 comeinto contact with the gaskets 518 of the fluid ports 516 on thereservoir card 500, forming fluid-tight seals. In the presentlypreferred embodiment, the seal between the gaskets 518 and the sealingfeatures 702 is a face seal. However, other types of seals or sealingfeatures (such as luer seals) could alternatively be employed forproviding a fluid-tight seal between the reservoir card 500 and testcartridge base 400 housing 401. Alternative sealing features couldinclude a radially compressible gasket (not shown) forming an annularseal. When the reservoir card 500 has been fully inserted into thereceiving slot 402 and the fluid-tight seals have been formed, one wayattachment features 502 (FIG. 5B) on the reservoir card 500 housing 501engage with complimentary retention features (not shown) on the testcartridge base 400 housing 401 in a manner well known in the art topermanently retain the reservoir card 500 in the assembled state withthe test cartridge base 400, thereby creating the test cartridgeassembly 300.

It will be appreciated by those skilled in the art that while aparticular reservoir card 500 component arrangement has been described,the present invention is not limited to this particular arrangement.Possible alternative arrangements include use of only a single reagent,storage of reagents 504, 506 in a larger cylindrical volume, oralternative fluid port protective features, such as pierced films orfoils and/or user removed coverings.

Referring to FIGS. 9, 10A, 10B and 10C, a fluid displacement mechanism900 within the test cartridge base 400 is shown. FIG. 9 is across-sectional side elevational view of the test cartridge assembly ofFIG. 3A introduced into the analysis portion 200. The plunger 424, whichis located in the test cartridge base 400 housing 401, is preferablydesigned to move air that travels through the air channels 902A-902D inthe test cartridge base 400 housing 401, through the sealing features702 formed between the assembled reservoir card 500 and the testcartridge base 400 housing 401. When actuated by the piston rod 224A,the plunger 424 causes the reagents 504, 506 stored in the reservoircard 500 to be displaced into the test cartridge base 400. As describedabove, the plunger 424 is preferably actuated by the piston rod 224A inthe analysis portion 200.

As they are displaced, the reagents 504, 506 are forced into the testcartridge base 400 housing 401, and eventually into the reaction chamber404. The design utilizing air to displace the reagents 504, 506 from thereservoir card 500 enables the fluid displacement mechanism 900components to be located in the test cartridge base 400 housing 401,which allows the reservoir card 500 to achieve a minimal volume tofacilitate storage and transport of the reservoir card 500. In thepreferred embodiment, the air channels 902A-D leading from the centralbore 422 and plunger 424 are designed to produce a staged delivery ofthe reagents 504, 506 from the reservoir card 500 to the reactionchamber 404. Referring to FIGS. 10A-10C, the delivery of the reagents504, 506 occurs as air is displaced from the central bore 422 through aseries of air channel ports 902 that are alternately sealed, and thenopened, as the plunger 424 moves along the central bore 422.

Referring to FIG. 10A, in the beginning or first stage, the plunger 424is positioned at a beginning end 906A of the central bore 422. Flanges908 of the plunger 424 initially seal off a first air channel port 902A,which is connected through a fluid port 516C to the storage area 512 forthe second reagent 506 in the reservoir card 500 and isolate the firstchannel port 902A from the other channel ports 902B-D and the firstreagent 504.

A second air channel port 902B is open and connected to a fourth airchannel port 902D. A third air channel port 902C is open and connectedto the first reagent 504 storage area 510. In the preferred embodiment,the first reagent 504 includes the biosensor used for performing thetest on the sample 414. As the plunger 424 is actuated by the piston rod224A, the plunger 424 travels further through the central bore 422, anddisplaced air from the central bore 422 travels through the third airchannel port 902C, displacing the first reagent 504 from the reservoircard 500. The first reagent 504 flows into the test cartridge base 400housing 401, and eventually into the reaction chamber 404 to mix withthe sample 414 in the above-described manner.

As the plunger 424 moves through a second stage toward the second end906B of the central bore 422, referring to FIG. 10B, the second airchannel port 902B becomes sealed off by the flanges 908. However, thesealing of the second air channel port 902B has no effect due to thedirect connection of the second air channel port 902B to the fourth airchannel port 902D. When the plunger 424 reaches the second stage of FIG.10B, the entire volume of the first reagent 504 will have been displacedfrom the reservoir card 500 to the test cartridge base 400 housing 401.At this time, the motion of the plunger 424 is paused with the secondair channel port 902B sealed off for the duration necessary to completethe first phase of the test by the testing device 100. In oneembodiment, the motion of the plunger 424 is paused for approximatelysixty (60) to one hundred twenty (120) or more seconds. The amount oftime the plunger 424 is paused preferably depends on the type of testbeing run by the testing device 100, and is determined based oninformation provided by a test cartridge 300 RFID tag 508 being read bythe testing device 100 after insertion into the cartridge recess 152.

After the first phase of the test is completed, if the second test is tobe performed, the plunger 424 is again moved by the piston rod 224A,causing the plunger 424 flanges 908 to seal off the third air channelport 902C and open the second air channel port 902B. As the plunger 424continues to move through the central bore 422 toward the second end906B, displaced air from the central bore 422 is forced to travelthrough the fourth air channel port 902D, to the second air channel port902B, and through the central bore 422 in the clearance region betweenthe plunger 424 and the central bore 422 surface to the first airchannel port 902A. The displaced air that travels through the first airchannel port 902A displaces the second reagent 506, which flows into thetest cartridge base 400 housing 401, and eventually into the reactionchamber 404 in order to perform the second or negative resultverification test phase.

The plunger 424 continues to move through the central bore 422, untilcontacting the second end 906B of the central bore 422, as shown in FIG.10C. By this time the majority of the second reagent 506 will have beendisplaced and flowed into the reaction chamber 404. Upon completion ofthe plunger's 424 motion from the first end 906A to the second end 906Bof the central bore 422, it is preferable that the plunger 424 may notbe moved back toward the first end 906A. This one-way motion of theplunger 424 helps to prevent the test cartridge assembly 300 from beingreused in a subsequent test.

The use of a single piston rod 224A and a single plunger 424 isdesirable to limit the use of additional parts in the test cartridgeassembly 300 and testing device 100 for cost reasons, manufacturingcomplexity reasons, and the reduction of sources of potentialinterference with the light sensor 206. However, it should beappreciated by those of ordinary skill in the art that the precisestructure of the fluid displacement mechanism 900 described above ismerely that of a currently preferred embodiment and that variations maybe made to the structure of the fluid displacement mechanism 900 withoutdeparting from the scope and spirit of this invention. Possiblealternative arrangements of the fluid displacement mechanism 900 includeutilizing multiple motors to control one specific actuation or more permotor, utilizing multiple plungers to displace one or more reagents 504,506 per plunger, using plungers to directly displace reagents 504, 506instead of using air as an intermediary, or using an alternate means ofdisplacing the reagents 504, 506, such as a compressible membrane orblister pack.

Referring to FIG. 11, a functional schematic hardware block diagram 1100of the electrical/electronic and other related components of thepreferred embodiment of the testing device 100 is shown. Operation ofthe testing device 100 is controlled by a microprocessor 1102. In thepreferred embodiment, the microprocessor 1102 is an applicationsprocessor, such as the FREESCALE SEMICONDUCTOR model numberMCIMX255AJM4A processor, which implements the ARM926EJ-S core withprocessor speeds up to 400 MHz. Even more preferably, the microprocessor1102 includes an integrated 10/100 Ethernet controller and a UniversalSerial Bus (USB) physical layer (PHY) 1108B. The microprocessor 1102provides user defined, general purpose input/output (I/O) pins or portsfor connection of additional peripheral devices (not shown), ashereinafter described. The microprocessor 1102 core operates between1.34V-1.45V average power supply voltage from the power supply system1126. It will be apparent to those skilled in the art that themicroprocessor 1102 may be replaced by one or more microprocessors orother control devices such as FPGAs or ASICs, having different and/oradditional features and functionalities without departing from the scopeof this invention.

The built in USB port 112 b and USB PHY 1108B integrated into themicroprocessor 1102 are used to provide a USB communication port 112 bthat allows the testing device 100 to communicate or receivecommunications from other USB devices (not shown). The testing device100 uses a USB client protocol that allows the USB port 112 b to serveas a client to other USB devices (not shown). The external connectionmay be used for retrieval and installation of upgraded software,transmission of test records to remote devices (not shown), downloadingtest information and uploading test results to a host computer, or thelike. Other driver circuitry could similarly be used if desired.

The testing device 100 further includes a flash read only memory (ROM)1104, a dynamic random access memory (RAM) 1106, and an Ethernet PHYinterface 1108A, each of which access and are accessed by themicroprocessor 1102 by way of individual parallel buses 1110 in a mannerwell known in the art. In the preferred embodiment, there are at leastsixty four megabytes (64 MB) of ROM 1104 and at least sixteen megabytes(16 MB) of SDRAM 1106. The RAM 1106 is a MICRON model MT48LC8M16A2P-7E:Gintegrated circuit organized by 2 Mb x 16 I/Os x 4 banks. The RAM 1106supports software executing within the microprocessor 1102. The ROM 1104is preferably a SAMSUNG model K9F1208U0C-PIB00 NAND flash memoryintegrated circuit. The ROM 1104 is a persistent memory that isresponsible for retaining all system software and all test recordsperformed by the testing device 100. Accordingly, the ROM 1104 maintainsdata stored therein even when power to the testing device 100 isremoved. ROM 1104 may be rewritten by a procedure well known to thoseskilled in the art, thereby facilitating the upgrading of systemsoftware of the testing device 100 executed by the microprocessor 1102,without having to add or replace any of the memory components 1104, 1106of the testing device 100. Different models from the same or differentmanufacturers may alternatively be used for the ROM 1104 and/or the RAM1106 if desired.

The microprocessor 1102 additionally has an integrated interface for amemory card Secure Digital expansion port and card reader 1112. The SDcard expansion port 1112 is located within the testing device 100 tofacilitate additional functionality in future iterations of the testingdevice 100 by introducing an SD memory card (not shown) havingadditional functionality stored thereon.

The Ethernet PHY interface 1108A is a model DP83640TVV integratedcircuit from NATIONAL SEMICONDUCTOR, and provides for a 100 MB persecond connection to a local area network (LAN), computer (not shown),or other external device (not shown). The Ethernet PHY interface 1108Anegotiates between a connected external device (not shown) and themicroprocessor 1102 via its individual parallel bus 1110C.

The testing device 100 requires several regulated voltages to besupplied in order to function properly. The various voltages areprovided by a multi-channel power management integrated circuit (PMIC)1116. The PMIC 1116 addresses power management needs of up to eight (8)independent output voltages with a single input power supply. In thepresent embodiment, the PMIC 1116 is a FREESCALE MC34704 IC, but otherpower management circuits may alternatively be used. The PMIC 1116provides standby outputs that are always actively supplying power to thereal-time clock in the microprocessor 1102 and the battery monitorcircuit (not shown).

The microprocessor 1102 controls its power supply system 1126, andenters into a sleep mode whenever the testing device 100 is inactive fora predetermined period of time (e.g., 10 minutes). At that time, mostinternal functions of the microprocessor 1102 are halted, therebypreserving the batteries 116. However, a real time clock (not shown) iskept running to maintain the correct date and time of day for thetesting device 100. In addition, one or more sensors, such as the touchscreen portion of the LCD 110, are preferably maintained in an activestate so that the sleep mode may be exited by, for example, sensing theuser depressing any portion of the touch screen, or opening the hingedlid 104 by depressing the actuator 106.

In the event that all electric power to the power supply system 1126 ofthe testing device 100 is removed, such as when the batteries 116 arereplaced, a battery recovery backup (not shown) attached to themicroprocessor 1102 maintains the minimal power necessary to power thereal time clock so that the testing device 100 can maintain the correctdate and time. The ability of the microprocessor 1102 to write to flashROM 1104 is inhibited whenever power is being removed or restored to thetesting device 100 until after the power supply system 1126 andmicroprocessor 1102 stabilize in order to prevent the accidentalaltering of the contents of the flash ROM 1102 while power is beingcycled.

A first port of the microprocessor 1102 is used for connecting themicroprocessor 1102 to the RFID communication circuit 210 via thesensor/RFID board interface 1118 and to the light sensing circuit 1200(FIG. 12) for receiving data therefrom. A second port of themicroprocessor 1102 is used for connecting the microprocessor 1102 toperipherals (not shown) via the Experiment Support Peripheral Interface1120. The light sensing circuit 1200 will hereinafter be described ingreater detail with reference to FIG. 12.

The light sensing circuit 1200 is capable of detecting multiple rangesand types of readings that are necessary for conducting the varioustypes of tests performed by the testing device 100. The light sensingcircuit 1200 includes a secondary microprocessor 1202, a fast pulsecounter 1204, one or more analog amplifiers and filters 1206, a PMT 206,and a PMT high voltage power supply 218. The PMT 206 detects lightsignals from the test cartridge assembly 300 on an active surface, andoutputs current pulses to the light sensing circuit 1200. In thepreferred embodiment, once the reagent 504 has mixed with the sample414, the PMT 206 begins to analyze the light signature for photons thatare not associated with normal radiation, photon emission from the testcartridge base 400 housing 401, and other mechanical noise from thetesting device 100. The output current pulses are converted by the lightsensing circuit 1200 and relayed by the secondary microprocessor 1202 ina digital format that is sent to the main microprocessor 1102 foranalysis.

The spectral response range of the PMT 206 varies from the ultravioletrange to the visible light range (230 nm-700 nm) with a peak response at350 nm and a photosensitivity response time of 0.57 ns. In the presentembodiment, the PMT 206 a model R9880U-110 and high voltage power supply218 is a model C10940-53, both manufactured by HAMAMATSU PHOTONICS. Thesecondary microprocessor 1202 is preferably a TEXAS INSTRUMENTS modelMSP430F2013IPW processor.

The secondary microprocessor 1202 provides a consistent interface fortransmitting data to the main microprocessor 1102. Accordingly, while itis desirable to include the secondary microprocessor 1202 in the testingdevice 100 within the light sensing circuit 1200 in order to providefuture flexibility and ease in implementing additional or alternativesensors 206, or scaling up the light sensing circuit 1200 to includemultiple detectors, the secondary microprocessor 1202 is optional. Thatis, the functionality of the secondary microprocessor 1202 mayalternatively be performed by the microprocessor 1102. In this case, thesensor 206 could be connected directly to a serial port on themicroprocessor 1102.

PMTs 206 are sensitive to sources of interference, such as temperaturechanges, electrical fields, magnetic fields, and electromagnetic fields.Thus, the area of the sensing surface of the PMT 206 is susceptible tothe output of unwanted signals, or background noise, due to these andother sources of interference. In the preferred embodiment, the diameterof the sensing surface of the PMT 206 is limited to 8 mm in order tolimit the generation of background noise signals and increase the signalto noise ratio (SNR) of the output of the light sensing circuit 1200. Itwill be apparent to those skilled in the art that other PMTs 206 andhigh voltage power supplies 218 may alternatively be utilized.

Returning to FIG. 11, the LCD 110 is driven by a LCD controllerintegrated in the microprocessor 1102, which generates the requiredsignaling format to the LCD 110. Accordingly, the LCD 110 is connectedto general purpose input/output ports of the microprocessor 1102 via thedisplay/touch panel interface 1122. The LCD 110 preferably includes anon-board drive circuit (not shown) that interfaces to the input/outputports of the microprocessor 1102 via standard data and control signals.The touch screen of the LCD 110 utilizes a four-wire connection forcommunication with the microprocessor 1102. A speaker 1124 may beconnected to the microprocessor 1102 to audibly output sounds, such aswarning and error messages, and the like to the user.

It should be appreciated by those skilled in the art that the variouselectrical/electronic components shown in FIGS. 11 and 12 are merely oneillustration of the electrical/electronic components of the preferredembodiment of the present invention. Other components may be substitutedfor or added to any of the components shown without departing from thescope of this invention. In other words, the present invention is notlimited to the precise structure and operation of theelectrical/electronic and related components shown in FIGS. 11 and 12.

Referring to FIG. 16, a flowchart of steps in which the test cartridgeassembly 300 is utilized in conjunction with the testing device 100 forperforming a test according to the preferred embodiment of thisinvention is shown. Before a test begins, a reservoir card 500 ismanufactured, preferably outside of the test setting. Engineered B cellsare grown at step 1610. The grown cells are charged with coelenterazineat step 1612, and excess coelenterazine is removed at step 1614. A cellstabilizer, such as pluronic F68 is added at step 1616, and acryopreservative, such as dimethyl sulfoxide (DMSO), is added at step1618 to complete creation of the biosensor (i.e., reagent 504). Thecells are loaded into the reservoir cards 500 at step 1620. At step1622, the positive control sample (i.e., reagent 506), such as anti-IgMor digitonin, is loaded into the reservoir cards 500. The reservoircards 500 are then frozen, stored and/or distributed to testing sites atstep 1624. Preferably, the cards are frozen and stored at a temperaturebelow approximately negative forty degrees Celsius (−40° C.).

Once the cards have been distributed, before the test begins, at step1626, the user may be required to prepare a reservoir card 500 of aselected test type by thawing the reservoir card 500 and the reagents504, 506 contained inside using a specified thawing procedure.Preferably, a thawing procedure is specified when required for aspecific reservoir card 500 test type. At step 1628, a user selects the(prepared) reservoir card 500 of the desired test type and assembles thereservoir card 500 into the test cartridge base 400 until the permanentattachment features 502 on the reservoir card 500 housing 501 engagewith the retention features in the test cartridge base 400 housing 401.In the currently preferred embodiment, audible (i.e., a click) and/ortactile feedback is evident to the user due to the permanent attachmentfeatures 502 on the reservoir card 500 engaging the retention featureson the test cartridge base 400 housing 401.

At step 1630, the user optionally prepares a sample 414 by, for example,fragmenting any infectious agent present in the sample 414 usingsonication, pressure gradient, and/or enzyme treatment, or the like.Several techniques may be used, including: (i) an enzyme such as lipaseto release O-antigens from the cell surface (part of LPS); (ii)sonication to fragment the cells; (iii) a French Press or equivalent tofragment the cells; or (iv) a chemical treatment to release LPS from thecells. At step 1632, the user employs a sample deposition tool to piercethe perforated film 410 on the test cartridge base 400 above thereaction chamber 404 and deposit a very small quantity (e.g., thirtymicro Liters) of a sample 414 of a suspected infectious agent directlyinto the reaction chamber 404 within the test cartridge base 400. Theuser then removes the sample deposition tool and closes the testcartridge base 400 integral hinged lid 408, ensuring that the retentionfeatures 408 a and 408 b engage with the slots 420 a and 420 b on thetest cartridge base 400 housing 401. The test cartridge base 400 hingedlid 408 is retained in the closed position, and the compressible gasket418 on the top surface of the test cartridge base 400 is engaged by thelid 408 to form a fluid-tight seal. At this time, the reagents 504, 506stored inside the reservoir card 500 must be fully thawed in order toproceed with the rest of the test. Alternatively, the user couldassemble the reservoir card 500 into the test cartridge base 400 afterdepositing the sample 414 in the reaction chamber 404 or before thereagents 504, 506 are thawed. Further, the sample 414 may be depositedinto the reaction chamber 404 after the test cartridge assembly 300 hasbeen inserted into the testing device 100.

Referring to FIGS. 1C and 3C, the bottom of the test cartridge assembly300 is designed to be placed into the cartridge recess 152 in order forthe lens 412 of the reaction chamber 404 to align with the sensor 206.The test cartridge assembly 300 and cartridge recess 152 are preferablyshaped in a way that the test cartridge assembly 300 cannot be fullyinserted in an improper orientation and/or the testing device 100 hingedlid 104 will not be able to close if the test cartridge assembly 300 isintroduced into the analysis portion 200 in an improper orientation.

When the user inserts the test cartridge assembly 300 into the cartridgerecess 152 in the proper manner, a physical process begins a chainreaction of physical and electronic processes within the testing device100 to perform the desired test on the sample 414 at step 1634 and, ifnecessary, a positive control test at step 1636. The user closes thehinged lid 104 of the testing device 100, which mechanically latches inthe closed position. The testing device 100 is capable of detecting whenthe hinged lid 104 is closed, and sends a signal to the microprocessor1102, which activates the RFID communication circuit 210 for datatransmission to and/from the RFID tag 508 via the RFID communicationscircuit 210.

At this time, the RFID tag 508 located within the test reservoir card500 is placed in the path of the RFID communications circuit 210 withinthe analysis portion 200. In the present embodiment, the RFID tag 508 isa RI-116-114A-S1 from Texas Instruments, which operates at 13.56 MHz andcontains 256 bits of user memory for read/write functionality. Thetesting device 100 reads detailed information for the test to beperformed from the test cartridge assembly 300 RFID tag 508 via RFID.Information which may be communicated to and from the RFID tags 508includes test lot or sample origin, the specific test to be performed,information concerning the identity of a particular test cartridge, aswell as other information. The testing device 100 also writes a value tothe test cartridge RFID tag 508, which signifies that the test cartridgeassembly 300 has been used to perform a test. The writing of the RFIDtag 508 prevents the test cartridge assembly 300 from being reused inthe same or any other compatible testing device 100 in the future.Referring to FIGS. 13A and 13B, the testing device 100 prompts the userto confirm the test type and to start the test via a user interface 1400(FIG. 14) displayed on the LCD 110, which will hereinafter be describedin greater detail.

Referring to FIGS. 2 and 9, when the user chooses to start the test, themicroprocessor 1102 sends a signal to actuate the motor 226, whichdrives the piston 224 and piston rod 224A forward to engage the fluiddisplacement mechanism 900, and to complete the introduction of thefirst reagent 504 to the reaction chamber 404 in the manner describedabove. The piston rod 224A also preferably functions as a hinged lid 104interlock. Thus, once the piston 224 begins to move under the force ofthe motor 226 at the start of the test, the piston rod 224A movesbeneath the actuator 106. When the piston rod 224A is beneath theactuator 106, mechanical interference between the two prevents the userfrom pushing down the actuator 106 and opening the lid 104 as aprecaution against user error while a test is in process. The piston rod224A remains beneath the actuator until the test is complete and thepiston 224 is fully retracted. Simultaneously to completing the firststage of the fluid displacement mechanism 900, the piston rod 224A movesthe sliding shutter 236 to its second position which exposes the surfaceof the sensor 206 to light emitted from the reaction chamber 404 of thetest cartridge assembly 300 via the sliding shutter aperture 238.

Since the reaction process preferably begins as soon as the fluiddisplacement mechanism 900 within the test cartridge assembly 300completes the first reagent 504 introduction to the reaction chamber404, the light sensing circuit 1200 is also activated at this time todetect any light emissions that may occur even before the user makes theappropriate data entry, as will hereinafter be described in greaterdetail. If the light sensing circuit 1200 detects an appropriate lightsignal, the microprocessor 1102 stores and reports a positive result,the light sensing circuit 1200 is turned off and the motor 226 moves toretract the piston 224 to its initial position.

The plunger 424 of the tested test cartridge assembly 300 remains at itsfinal position even after the piston 224 has been retracted. The usermay then open the hinged lid 104 by pressing the actuator 106 and removethe used test cartridge assembly 300 for proper disposal. The testsample 414 and the reagents 504, 506 are all sealingly contained withinthe test cartridge assembly 300. The user may also confirm a result ofthe test within the user interface (FIG. 15) displayed on the testingdevice 100 LCD. Alternatively, if a predetermined length of time (e.g.,60-120 seconds) elapses during the initial test and the light sensingcircuit 1200 has not detected an appropriate light signal, the motor 226preferably moves to drive the piston 224 further into the fluiddisplacement mechanism 900 until completion of the introduction secondreagent 506 into the reaction chamber 404 for the performance of thesecond test, as described above.

If the light sensing circuit 1200 does not detect an appropriate lightsignal as a result of the second test, the microprocessor 1102 storesand reports an error message. However, if as a result of the second testthe appropriate light signal is detected by the light sensing circuit1200, the microprocessor 1102 stores and reports a negative result. Atthis time, the light sensing circuit 1200 is turned off and the motor226 moves to retract the piston 224 to its initial position. The usermay then remove the used test cartridge assembly 300 for properdisposal. At this time, the testing device 100 is reset and is ready forreceiving another test cartridge assembly 300. Subsequent testing may beconducted in the same manner (using a new test cartridge assembly 300)as described above.

As previously discussed, the testing device 100 has the capability ofperforming a variety of different real-time (or near real-time) testsusing a single disposable test cartridge assembly 300 containing areservoir card 500 which has been specifically designated to perform aparticular test. Each reservoir card 500 contains a predeterminedreagent mixture 504, 506 for performing a particular test. The RFID tag508 within the reservoir card 500, as well as the reservoir cardlabeling (not shown) identifies the particular test that reservoir card500 is to perform, as well as the relevant control parameters for theparticular test. In this manner, the testing device 100 is adapted forautomatic customization, through software, for the performance ofvarious tests.

An exemplary first reagent 504 is a biosensor reagent which includes ahuman B lymphocyte engineered to express a bioluminescent protein and atleast one membrane-bound antibody specific for a predeterminedinfectious agent. With regard to biosensors, cell-based biosensor (CBB)systems that incorporate whole cells or cellular components respond in amanner that can offer insight into the physiological effect of ananalyte. As will be appreciated by those skilled in the art, cell-basedassays (CBA) are emerging as dependable and promising approaches fordetecting the presence of pathogens in clinical, environmental, or foodsamples because living cells are known to be extremely sensitive tomodulations or disturbances in “normal” physiological microenvironments.Therefore, CBB systems have been employed to screen and monitor“external” or environmental agents capable of causing perturbations ofliving cells (see, for example, Banerjee et al., Mammalian cell-basedsensor system, Adv. Biochem. Eng. Biotechnology, 117:21-55 (2010), whichis incorporated by reference herein.)

Compared with traditional detection methods (e.g., immunoassays andmolecular assays such as PCR), a biosensor provides several advantagesincluding,

-   -   (i) speed, i.e. detection and analysis occurs in several seconds        to less than 10 minutes;    -   (ii) increased functionality, which is extremely important for        reporting active components such as live pathogens or active        toxins, and    -   (iii) ease of scale-up for performing high-throughput screening.

An aequorin-based biosensor system is utilized with certain embodimentsof the present invention. Aequorin is a 21-kDa calcium-bindingphotoprotein isolated from the luminous jellyfish Aequorea victoria.Aequorin is linked covalently to a hydrophobic prosthetic group(coelenterazine). Upon binding of calcium (Ca2+) and coelenterazine,aequorin undergoes an irreversible reaction, and emits blue light(preferably 469 nm). The fractional rate of aequorin consumption isproportional, in the physiological pCa range, to [Ca2+]. Application ofthe aequorin-Ca2+ indicator to detect E. coli contamination in foodproducts was reported in 2003 (see, Rider et al. A B cell-based sensorfor rapid identification of pathogens, Science, 301(5630):213-5 (2003),which is incorporated by reference herein). In Rider, engineered Blymphocytes were used to express antibodies that recognize specificbacteria and viruses. The B lymphotcytes were also used to expressaequorin, which emits light in response to the calcium flux triggered bythe binding of a cognate target to the surface-antibody receptor. Theresulting biosensor cell emitted light within minutes in the presence ofthe targeted microbes. To create such biosensor cells, antibody heavyand light chains with variable regions were cloned and expressed in aB-lymphocyte cell line. The resulting immunoglobulins become part of asurface B-cell-receptor complex, which includes the accessory moleculesimmunoglobulinα (Igα, or CD79a) and immunoglobulinβ (Tgβ, or CD79b).When the complex is cross-linked and clustered by polyvalent antigens,such as microbes, a set of signaling events quickly leads to changes inthe intracellular calcium-ion concentration, which then causes aequorinto emit light. This mechanism essentially hijacks the B-cell's intrinsiccapacity to specifically recognize the antigen presented in the E. coliby the B-cell membrane IgG antibody, and this binding triggers atransient Ca2+ influx to cytosol, which binds the aequorin proteinsengineered in this B-cell, and subsequently emit blue light. See,Reiman, Shedding light on microbial detection, N England J Med,349(22):2162-3 (2003), which is incorporated by reference herein, in itsentirety.

Selection of an appropriate B cell is important to the describedtesting. Therefore, any proposed cell line should be tested to confirmthat the B cell receptor signaling pathway is fully functional.Individual B cell clones having the aequorin gene should be tested toidentify a particular clone with high aequorin activity, as significantvariation from one clone to the next is possible (see, generally, Calpeet al., ZAP-70 enhances migration of malignant B lymphocytes towardCCL21 by inducing CCR7 expression via IgM-ERK1/2 activation, Blood,118(16):4401-10 (2011) and Cragg et al., Analysis of the interaction ofmonoclonal antibodies with surface IgM on neoplastic B-cells, Br JCancer, 79(5/6): 850-857 (1999), both of which are incorporated byreference herein in their entirety).

A high-aequorin expressing B cell is important for achieving high levelsof sensitivity when using this detection system. In an exemplaryembodiment, the receptor response for the biosensor was verified byusing the Ramos human B cell line. Ramos cells are first transfectedwith the aequorin gene and the transfected cells were then selected forthe aequorin expression for two weeks. Thereafter, mixed Ramos cells arecharged with coelenterazine (CTZ), and stimulated with anti-IgM Ab. Theelicited flash signal is captured by a luminometer.

As shown in FIG. 17, anti-IgM stimulation causes an expected sizeableand prolonged flash (from 45 to 65 seconds). In FIG. 17, the Y-axisrepresents the amount of light flashing, and the X-axis represents thereaction time in seconds. At thirty (30) seconds, the anti-IgM solutionis injected into the Ramos-aequorin cell solution. The first spike (from30-37 seconds) is a noise signal, and the second larger and longer peakis the biological response to anti-IgM stimulation. To improve theoverall signal/noise ratio, the CTZ is removed from the CTZ-chargedRamos-aequorin cells solution. Removal of CTZ from the cell solutiondecreases the noise signal from around one hundred fifty (150) to aboutfifty (50), without significant compromise of the amount of the truepeak signal.

In accordance with the present invention, an exemplary protocol for cellhandling and flash-testing includes: (i) culturing Ramos-aequorin cellswith a regular culture medium and keeping these cells healthy (i.e.,viability >98%); (ii) charging the Ramos-aequorin cells with CTZ at afinal concentration of 2 μM, the cell density being 1-2 million permilliliter; (iii) charging the cells at 370° C. with 5% CO₂ in anincubator for at least 3 hours; (iv) removing the charging mediumcontaining CTZ; (v) flash testing by taking 200 μl cell solution plus 30μl stimulants (anti-IgM) and reading with a luminometer; and (vi)confirming the CTZ and aequorin functionality by adding 30-40 uLdigitonin (770 μM).

The testing device 100 is preferably controlled by an operating systemexecuted by the microprocessor 1102. In the present embodiment, theoperating system is preferably a custom designed and programmedapplication running in the Linux environment. The operating systemprovides input/output functionality, and power management functions, asdescribed. The custom application includes a simple, menu-based userinterface, as shown in FIGS. 14 and 15; parameter-driven functions tocontrol and analyze the tests performed by the testing device 100; and afile system to store test protocols and results. Stored test results canbe recalled, displayed or printed out. The software allows for theaddition of protocols for new tests through file downloading, or thelike.

The user interface 1400 of FIG. 14 is preferably menu driven, with aseries of items selectable by a user using menus provided on the touchscreen LCD 110. Preferably, the user interface 1400 presents a series ofchoices that allows navigation to and through each specific test untilcompletion thereof. In the present embodiment, the user interface 1400allows the user to return to the previous screen by using a back keyprovided on the LCD and touch screen. However, use of the back key whiletesting is not allowed unless the test is cancelled or aborted. Aselected action may proceed through a series of steps with each stepbeing indicated by a new prompt to the user.

FIGS. 13A and 13B are a flowchart showing the basic flow of a preferredembodiment of the computer software employed by the testing device 100.It will be appreciated by those skilled in the art that the software mayfunction in a slightly or completely different manner than the mannershown in FIGS. 13A and 13B, which is included merely to illustrate acurrently preferred way for the software to function.

The process begins at step 1300, where a splash screen is presented tothe user on the display 110 while the application completes loading onthe testing device 100. At step 1302 and 1304, a user is prompted with auser name and password entry process. The testing device 100 verifiesthat the entered user name and password are valid, and proceeds to ahome screen 1400 (FIG. 14) at step 1306. A user identifier (e.g., afive-digit code) uniquely identifying the user performing the test ispreferably stored by the testing device 100 as part of a test record.

The user selects one or more actions and/or functions of the testingdevice 100 to be performed from the home screen 1400, including runninga test (step 1308) by inserting a test cartridge assembly 300, reviewinglogged results (step 1310) by pressing Test Log button 1402 orconfiguring settings (step 1312) such as Time Zone (Step 1330) orLanguage (Step 1332) by pressing button 1404. Preferably, the userselects the desired action using the touch screen LCD 110 of the testingdevice 100.

If the user inserts a test cartridge assembly 300 into the testingdevice 100 and closes the hinged lid 104, the RFID communicationscircuit 210 is activated after the hinged lid 104 is closed, and theRFID tag 508 or other identification on the installed test cartridgeassembly 300 identifies the type of test that the testing device 100 isto perform.

Preferably, each RFID tag 508 stores a character string, which encodesthe particular type of test for the test cartridge assembly 300, anexpiration date for each test cartridge assembly 300, a test cartridgeassembly 300 serial number, which may include a testing solution lotnumber, whether the test cartridge assembly 300 has previously beentested within a testing device 100, as well as other informationpertaining to a particular test cartridge assembly 300. Taken together,the information presented in the RFID character string uniquelyidentifies each test cartridge assembly 300. The test cartridge assembly300 information is entered into the testing device 100 when the testcartridge assembly 300 is inserted into the cartridge recess 152 in theanalysis portion 200 and the hinged lid 104 is closed. The processchecks the scanned test cartridge RFID tag 508 data to confirm that thetest cartridge has not been used before. RFID tag 508 data scanned fromthe test cartridge are accepted as valid if the RFID communicationscircuit 210 detects no RFID transmission error during the scanningprocess and the data format of the RFID tag 508 is valid. Upondetermining that the hinged door 104 is closed and that the data readfrom RFID tag 508 is valid, the Run test option of step 1308 isautomatically selected, and the user is prompted to confirm that thetesting device 100 is to run the test.

While the test begins, the user begins the required data entry. The useris prompted to enter the specific numeric code of the sample 414 intothe touch screen LCD 110 at step 1314, where the user is prompted toenter a “Sample/Location” type. In the preferred embodiment, the numericcode of the sample 414 comprises a five digit number that relates to alot or environment of the sample 414. If the user selects “Sample,” atstep 1316, the user is prompted to enter a lot number using the touchscreen LCD 110. If the user selects “Location,” at step 1318, the useris prompted to enter a location using the touch screen LCD 110.

Upon receiving the sample specific code, the information received fromthe RFID tag 508 of the test cartridge assembly 300 and the receiveduser data entry are compared to all stored test records, as well as thedata received from the RFID tag 508 signifying whether the testcartridge assembly 300 has previously been tested, and rejects the testcartridge assembly 300 if that test cartridge assembly 300 has beentested before.

The information read from the RFID tag 508 is also used to identify theparticular test to be performed by the testing device 100, and to selectthe appropriate test protocols. Protocols to be selected include testtiming, light reading requirements from the light sensing circuit 1200,and the like for the particular test to be performed. The parametersfrom a test control table stored in the ROM 1104 specify how each stepof the test data acquisition and analysis is to be performed, includingalternate software routines where necessary. In this manner, new ormodified test parameters can be installed by downloading new testcontrol tables and, if necessary, supporting software modules, withoutmodification of the basic operating or application software. Informationfrom test control tables is stored in the ROM 1104 for each diagnostictest which could potentially be performed utilizing the testing device100. In alternate embodiments, additional information relating to thetest samples 414 may also be included in the test initiation process ofthe testing device 100. Such additional information may include handlingrequirements, quarantine requirements and other anomalouscharacteristics of test samples 414.

The testing device 100 performs the test on the sample 414 while theuser enters the sample 414 specific numeric code, and continues toperform the test after the user has completed the required data entry.The test is preferably only completed after the user completes therequired data entry. Applying force to open the hinged lid 104, orfailing to complete data entry results in a failed or aborted test.Preferably, the users of the testing device 100 understand that thetesting device 100 requires that all data entry be fulfilled and thatthe hinged lid 104 must remain closed to minimize failed or abortedtests.

At step 1320, a status of the test is shown to the user. The testingdevice 100 displays the status information to the user to confirm thatthe test is in process until the test is complete. Test information,whether prospective, in process or completed, is displayed on the LCDscreen 110 in a fixed, text format that includes the test cartridgeassembly 300 identifying information described above. Elements of thetest record which are not yet completed are either left blank ordisplayed as “in progress” until the test is completed. Preferably, theuser cannot perform other functions on the testing device 100 while atest is running. However, in other embodiments, the software may bealtered to allow the user to perform other tasks on the testing device100, such as reviewing a test log, while a test is being performed.

If during the test, it is determined that an appropriate light signal isdetected by the sensor 206, the process proceeds to step 1322, where apositive result is reported, and the user is prompted to confirm. Oncethe user confirms, the user is prompted to re-enter the Lot/Locationnumber at step 1324. If the Lot/Location number matches, the test datais logged and the process returns to the home screen of step 1306. If atstep 1320, an appropriate light signal is not detected by the sensor206, the process checks whether an appropriate light signal is detectedfor the negative control test. If so, the negative result is reported,as shown in the Negative Result screen 1500 of FIG. 15 and the user isprompted to remove the cartridge at step 1326. At this point, no RFIDsignal is detected and the test data is logged, with the processreturning to the home screen of step 1306.

In addition, a test can be aborted by the software at any stage if, forexample, the sensor 206, the motor 226, or any other hardware failure isdetected or if the hinged lid 104 is opened. If at step 1320, such anissue is detected, a test error is reported at step 1328, and the useris prompted to remove the used test cartridge assembly 300. Once thetest cartridge assembly 300 is removed, no RFID signal is detected bythe RFID communications circuit 210, the error data is logged in ROM1104, and the process returns to the home screen 1400 of step 1306.Similarly, the test can also be cancelled by the user at any stage untilthe test results are reported and stored. Aborted and cancelled testsare recorded in the test result file and stored in the flash ROM 1104 toprevent reuse of a previously used test cartridge assembly 300.

Test results are stored in the flash ROM 1104 in text form, preferably,as displayed on the touch screen LCD 110. Each test record preferablyincludes all of the above identified test information, including theidentification of the test sample 414, the particular test performed,the date and time of the test, user ID and either a standard result oran identification that the test failed due to an error or was aborted.

All test results from either successfully completed or failed tests arestored in the flash ROM 1104. The user can recall the test results fromthe flash ROM 1104 to display on the touch screen LCD 110. Preferably,the flash ROM 1104 is large enough to store a substantial number of testrecords (e.g., five thousand records), preferably corresponding to thenumber of tests which could be expected to be performed in at least aweek of testing by the testing device 100. It is contemplated that theuser cannot delete records stored in the flash ROM 1104 in order toprevent unauthorized tampering with the test results. However, if theflash ROM 1104 is completely filled, the testing device 100 mayautomatically transition out of test mode and prompt the user to beginuploading data to a remotely located computer (not shown) via theinterface ports 112. Once the upload is complete and the test recordsare deleted from the flash ROM 1104, the user may again perform testsusing the testing device 100.

Conservation of battery power is an important concern which is addressedby the operating software at two levels. First, the current batterycharge level is provided to the user on a periodic or continuous basis.The software also provides specific prompts to the user to initiate arecharging of the batteries 116 when the battery monitor circuitindicates that the batteries 116 charge level has fallen below apredetermined safe limit. Further, the software precludes the initiationof a new test when the battery charge level in the batteries 116 is toolow for the safe completion of a test without risking a malfunction ofthe sensor 206, or other software or hardware function associated withthe test function of the testing device 100.

Power supplied to the various peripheral devices, including the RFIDcommunications circuit 210, the light sensing circuit 1200, the touchscreen LCD 110 and the microprocessor 1102 is controlled by theoperating system. Thus, supply of power may be selectively switched offwhen the functions of the various devices are not needed for currentoperation of the testing device 100. The entire testing device 100 mayalso be placed into a “power down” state upon receiving a user command,or after a predetermined period of inactivity of the testing device 100.The power down state differs from the complete absence of power in thatthe date/time clock continues to operate and the RAM 1106 is maintainedon power from the batteries 116 instead of the recovery battery backup,which activates upon complete power absence from the battery pack.

However, when the power down occurs, nearly all software activity ceasesexcept for the processes required to monitor the state of the touchscreen LCD 110. The user may “power up” the unit by touching the touchscreen LCD 110. As previously mentioned, upon detection of therestoration of batteries 116 power after a total power loss, thesoftware does not require the entry of date and time information as therecovery battery backup maintains this minimal function. In the presentembodiment, the time period set for the testing device 100 toautomatically power down based on a period of inactivity depends onwhich menu is displayed. The delay periods are preferably adjustableusing the settings menu of step 1312.

It will be appreciated by those of ordinary skill in the art thatchanges and modifications may be made to the embodiments described abovewithout departing from the spirit and scope of the invention. Therefore,the present invention is not limited to the embodiments described abovebut is intended to cover all such modifications within the scope andspirit of the invention. It will be appreciated by those skilled in theart that alternative arrangements of the test cartridge assembly 300,including the combination of reservoir card 500 and test cartridge base400 into a single subassembly, storing some of the necessary reagents504, 506 on both the test cartridge base 400 and reservoir card 500, ordirect sample deposition into the necessary reagents 504, 506 forperforming the desired test, are all within the scope of thisdisclosure.

We claim:
 1. A system for rapidly detecting the presence of aninfectious agent in a biological sample, comprising: a. a singlebiosensor reagent including at least one antibody specific for apredetermined infectious agent and a bioluminescent agent, wherein theat least one antibody is expressed on the surface of living, engineeredB-lymphocytes and wherein the bioluminescent agent is aequorin expressedby the living, engineered B-lymphocytes, the biosensor reagent beingoperative to: (i) detect the presence of a specific infectious agent ina biological sample to be tested, and (ii) emit a detectable lightsignal when the biosensor reagent reacts with the biological sample anddetects the presence of the specific infectious agent in the biologicalsample; b. a single-use, disposable test cartridge, wherein thesingle-use, disposable test cartridge includes: (i) a reservoir card,wherein the reservoir card further includes the biosensor reagent; (ii)a test cartridge base, wherein the test cartridge base is configured toaccept the reservoir card and wherein the test cartridge base furtherincludes: (a) a single reaction chamber having a central axis, whereinthe single reaction chamber has the shape of a revolved half ellipse;(b) an inlet channel connected to the reaction chamber, wherein theinlet channel is positioned above the reaction chamber at an angle of15-60 degrees above the horizontal, and wherein the inlet channel isoffset from the central axis of the reaction chamber; and (c) whereinupon introducing the biological sample into the test cartridge basethrough the inlet channel, the biological sample is homogeneously mixedwith the biosensor reagent while minimizing damage to the living,engineered B-lymphocytes and minimizing any bubbling of the mixedbiosensor reagent and biological sample in the reaction chamber; and c.a testing unit adapted to receive the single-use, disposable testcartridge, the testing unit including a sensor for detecting thedetectable light signal emitted by the biosensor reagent upon reactingwith the biological sample, the detection of the emitted detectablelight signal being indicative of the presence of the infectious agent inthe biological sample and being the only analysis of the emitteddetectable light signal that is performed, wherein detection of thespecific infectious agent in the biological sample occurs in real time.2. The system of claim 1, wherein the sensor is a photomultiplier tubehaving an active surface, and wherein the size of the active surface isoptimized to reduce background noise and increase the signal to noiseratio of the emitted light detectable signal.
 3. The system of claim 1,wherein the reservoir card is configured to be inserted into the testcartridge base, and to be permanently retained therein by one or moreretention features.
 4. The system of claim 3, wherein the test cartridgebase further comprises a fluid displacement mechanism including aplunger, and wherein actuation of the plunger causes the biosensorreagent stored in the reservoir card to be displaced into the reactionchamber.
 5. The system of claim 4, wherein the testing unit furthercomprises a motor and piston assembly configured to actuate the plunger.6. The system of claim 1, wherein the testing unit is a portable testingunit.
 7. The system of claim 1, further comprising at least one additivelocated in the test chamber, the at least one additive being operativeto minimize the formation of bubbles in the test chamber during mixingof the biological sample and the biosensor reagent.
 8. The system ofclaim 7, wherein the at least one additive includes a surfactant.
 9. Thesystem of claim 1, further comprising a disruptor for disruptingindividual cells of an infectious agent in the biological sample priorto mixing the biological sample with the biosensor reagent.
 10. Thesystem of claim 9, wherein the disruptor is at least one of an enzymeoperative to release O-antigens from the cell surface, a sonicatoroperative to fragment the cells, a French Press operative to fragmentthe cells, and a chemical treatment operative to release LPS from thecells of the infectious agent.
 11. The system of claim 1, wherein thebiosensor reagent is pre-charged with coelenterazine, and wherein anyexcess coelenterazine is removed from the biosensor reagent prior toreacting the biosensor reagent with the biological sample to be tested.12. The system of claim 1, wherein the biological sample to be tested isderived from food including at least one of beef, poultry, pork andother meats, fish, and vegetable matter.
 13. The system of claim 1,wherein the specific infectious agent is Escherichia coli.
 14. Thesystem of claim 1, wherein real time is within the range of within aboutfive minutes from combining the biological sample and the biosensorreagent.
 15. The system of claim 1, further comprising a second controlreagent operative to react with the biosensor reagent to determine aproper functioning of the testing unit, wherein the biosensor reagentreacts with the biological sample to be tested prior to the secondcontrol reagent reacting with the biosensor reagent.
 16. A testingdevice for real time detection of an infectious agent in a biologicalsample, the testing device comprising: a. a housing comprising a lid andan input/output device; b. an analysis portion comprising: (i) a recessin the housing for accepting a single-use, disposable test cartridgecontaining a biological sample to be tested, wherein the single-use,disposable test cartridge includes: (a) a reservoir card, wherein thereservoir card further includes a single biosensor reagent; (b) a testcartridge base, wherein the test cartridge base is configured to acceptthe reservoir card and wherein the test cartridge base further includes:i) a single reaction chamber having a central axis, wherein the singlereaction chamber has the shape of a revolved half ellipse; ii) an inletchannel connected to the reaction chamber, wherein the inlet channel ispositioned above the reaction chamber at an angle of 15-60 degrees abovethe horizontal, and wherein the inlet channel is offset from the centralaxis of the reaction chamber; and (ii) an actuator for interacting withthe single-use, disposable test cartridge when the lid is closed, theactuator causing the single biosensor reagent in the single-use,disposable test cartridge to be displaced to react with the biologicalsample during the performance of a test, the biosensor reagent includingat least one antibody specific for a predetermined infectious agent anda bioluminescent agent; wherein the at least one antibody is expressedon the surface of living, engineered B-lymphocytes and wherein thebioluminescent agent is aequorin expressed by the living, engineeredB-lymphocytes and wherein upon introducing the biological sample intothe test cartridge base through the inlet channel, the biological sampleis homogeneously mixed with the biosensor reagent while minimizingdamage to the living, engineered B-lymphocytes and minimizing anybubbling of the mixed biosensor reagent and biological sample in thereaction chamber; and (iii) a sensor associated with the recess in thehousing to detect a light signal emitted after the at least onebiosensor reagent has been displaced by the actuator to react with thebiological sample and to generate an output signal; and c. a controlunit configured to: (i) receive an input from a user via theinput/output device to initiate a test; (ii) in response to receivingthe user input and after the biological sample has been deposited in therecess of the analysis portion, actuate the actuator to displace the atleast one biosensor reagent in the test cartridge to react with thebiological sample; (iii) receive the output signal from the sensor; and(iv) output a test result to the user on the input/output device. 17.The testing device of claim 16, wherein the sensor is a photomultipliertube having an active surface, and wherein the size of the activesurface has been optimized to reduce background noise and increase thesignal to noise ratio of the emitted signal.
 18. The testing device ofclaim 17, further comprising an RFID communications circuit forreceiving one or more signals from the test cartridge, wherein the oneor more signals identify at least one of a test type to be run andwhether the test cartridge was previously used.
 19. The testing deviceof claim 16, wherein the biosensor reagent is pre-charged withcoelenterazine, and wherein any excess coelenterazine is removed fromthe biosensor reagent prior to reacting the biosensor reagent with thesample to be tested.
 20. The testing device of claim 16, furthercomprising a disruptor for disrupting individual cells of an infectiousagent in the sample prior to mixing the sample with the biosensorreagent.
 21. The testing device of claim 20, wherein the disruptor is atleast one of an enzyme operative to release O-antigens from the cellsurface, a sonicator operative to fragment the cells, a French Pressoperative to fragment the cells, and a chemical treatment operative toelease LPS from the cells of the infectious agent.
 22. The testingdevice of claim 16, wherein the testing device is a portable testingdevice.